Perioperative Fracture Risk and Two-Year Survivorship of a Short Tapered Femoral Stem following Direct Anterior Approach Cementless Total Hip Arthroplasty with a Fracture Table

The cementless, tapered wedge, short femoral stem implant is commonly used in direct anterior approach (DAA) total hip arthroplasty (THA). The lack of access and visualization, however, may increase the risk of perioperative fracture and early failure. Therefore, the current study examined perioperative complications and 2-year implant survivorship following DAA THA performed using a fracture table and short, tapered wedge femoral stem. A retrospective analysis was conducted on patients having undergone DAA THA with a cementless, tapered wedge, short femoral stem. Perioperative fractures were noted and survivorship was determined by the incidence of revision surgery within a minimum 2-year follow-up period. A total 366 consecutive patients (441 hips) were identified in the cohort. Four patients (6 hips; 1.4%) were lost to follow-up and three patients died from unrelated causes. Average follow-up time for the remaining 359 patients (435 hips) was 32.9 ± 10.2 months. There were no intraoperative factures but three perioperative fractures within two weeks. Aseptic loosening occurred in one stem at 13 months, resulting in a 99.1% survival rate with a mean survival time of 23.8 ± 0.1 months (95% confidence interval: 23.6–24.0 months). The use of a short, tapered wedge femoral stem and a fracture table for DAA THA resulted in 0.7% periprosthetic fractures and only one aseptic loosening within 2 years. These results suggest that proper femoral exposure with the use of a fracture table and a short, tapered wedge femoral stem does not appear to increase the risk of periprosthetic femoral fracture.

Migration analysis of a metaphyseal-anchored short femoral stem in cementless THA and factors affecting the stem subsidence

Background Early femoral stem subsidence following a cementless THA is correlated with aseptic loosening of the femoral component. The short femoral stems allow bone sparing and implantation through a minimally invasive approach; however, due to their metaphyseal anchoring, they might demonstrate different subsidence pattern than the conventional stems. Methods In this prospective single-center study, a total of 68 consecutive patients with an average age of 63 years, and a minimum follow-up of 5 years following a cementless THA with a metaphyseal-anchored short femoral stem were included. The femoral stem subsidence was evaluated using “Ein Bild Roentgen Analyse” (EBRA). Results Average stem migration was 0.96 +/− 0.76 mm at 3 months, 1.71 +/− 1.26 mm at 24 months, and 2.04+/− 1.42 mm at last follow-up 60 months postoperative. The only factor that affected migration was a stem size of 6 or more (r2 = 5.74; p = 0.039). Subdivision analysis revealed, that only in females migration appeared to be affected by stem size irrespective of weight but not in men (female stem size of 6 or more vs. less (Difference = − 1.48 mm, R2 = 37.5; p = 0.001). Migration did not have an impact on clinical outcome measures. Conclusions The examined metaphyseal-anchored short femoral stem showed the highest subsidence within the first 3 months postoperative, the implant began to stabilize at about 24 months but continued to slowly migrate with average total subsidence of 2.04 mm at 5 years following the THA. The amount of stem subsidence was not associated with worse clinical outcomes such as HHS, patient satisfaction, or pain.

An Alternative Femoral Stem-bone Implantation Technique Using an Innovative Short Femoral Stem Endoprosthesis

Arthroplasty of the hip, for either arthritic changes or femoral neck fracture, is a common procedure in orthopedic surgery. Although the standard designs for implantation, either cemented or uncemented, are well described and studied, there are also alternative designs regarding the implantation of both prosthetic stem and cup. This paper aims to explore one such alternative design, using the screw-in technique. It has been described in past literature for uncemented fixation of both the cup and the stem, and the biomechanical principles of fixation are different from the classical methods, offering certain advantages that are insufficiently explored in current-day endoprosthesis. Also, we will be presenting an innovative femoral stem design, recently developed, that combines an uncemented screw-on technique with a cemented augmentation possibility, aimed to provide the practitioner with the advantages of a bone-preserving mini-stem design, combined with the innovative screw-in fixation technique and the versatility of the hybrid cemented/uncemented fixation method.

Primary stability of a short bone-conserving femoral stem

AimsThe aim of this study was to determine the stability of a new short femoral stem compared with a conventional femoral stem in patients undergoing cementless total hip arthroplasty (THA), in a prospective randomized controlled trial using radiostereometric analysis (RSA).Patients and MethodsA total of 53 patients were randomized to receive cementless THA with either a short femoral stem (MiniHip, 26 patients, mean age: 52 years, nine male) or a conventional length femoral stem (MetaFix, 23 patients, mean age: 53 years, 11 male). All patients received the same cementless acetabular component. Two-year follow-up was available on 38 patients. Stability was assessed through migration and dynamically inducible micromotion. Radiographs for RSA were taken postoperatively and at three, six, 12, 18, and 24 months.ResultsAt two years, there was significantly less subsidence (inferior migration) of the short femoral stem (head, 0.26 mm, 95% confidence interval (CI) 0.08 to 0.43, sd 0.38; tip, 0.11 mm, 95% CI -0.08 to 0.31, sd 0.42) compared with the conventional stem (head, 0.62 mm, 95% CI 0.34 to 0.90, sd 0.56, p = 0.02; tip, 0.43 mm, 95% CI 0.21 to 0.65, sd 0.44, p = 0.03). There was no significant difference in dynamically inducible micromotion, rate of complications or functional outcome.ConclusionThis study demonstrates that the short femoral stem has a stable and predictable migration. However, longer-term survival analysis still needs to be determined. Cite this article: Bone Joint J 2018;100-B:1148–56.

Short Femoral Stem in Total Hip Arthroplasty: Stable Fixation and Low Complication Rates in Elderly Patients

Background We present the result of our experience in using a short femoral stem in elderly patients (>70 years of age) compared to patients younger than 70 years. Methods Data were prospectively collected on 138 patients who underwent 148 primary total hip arthroplasty (THA), with a conservative short stem between November 2010 and June 2014. The cohort was divided into 2 groups: the study group (group 1) comprised 57 patients (60 THA) over 70 years of age at the time of surgery, with a mean age of 75.4 years (range 70-87 years) and a mean follow-up of 26.7 months (range 9-48 months). The control group (group 2) comprised 81patients (88 THA) less than 70 years of age with a mean age of 57.4 years (range 33-69 years) and a mean follow-up of 27.3 months (range 9-54 months). Hip function in the 2 groups was compared preoperatively and postoperatively using the Merle D'Aubigne hip score (MD) and Western Ontario and McMaster Universities Arthritis Index (WOMAC) score. Results At the latest follow-up, 1 calcar fracture was reported in a 54-year-old patient in the control group, which required fixation with a screw and had a favourable outcome. No cases of clinical or radiographic loosening were reported. Clinical results showed no statistically significant differences between the 2 groups. Conclusions The use of the GTS conservative short stem in patients over 70 years old has shown very good results and low complication rates, comparable to those for patients younger than 70 years.

Mid-Term Outcome of Total Hip Arthroplasty Using a Short Stem

Purpose To review the outcome of total hip arthroplasty (THA) using a short femoral stem in 33 hips. Methods Records of 33 hips in 20 men and 10 women aged 25 to 40 (mean, 30) years who underwent cementless THA using a short femoral stem by a single senior surgeon were reviewed. The diagnosis included avascular necrosis (n=9), ankylosing spondylitis (n=12), rheumatoid arthritis (n=7), post-traumatic arthritis (n=4), and Hurler syndrome (n=1). Clinical outcome was assessed using the Harris Hip Score. Radiological outcome was assessed according to a modified Gruen zoning system. Stem positioning (neutral, varus, valgus) and bone contact were evaluated, as were fixation and early host response as well as subsidence and changes in the calcar region (zone 5). Trabecular response (trabecular attachment), spot welds, cortical hypertrophy, and pedestal formation were determined. Heterotopic ossification was graded by the Brooker classification. Results The mean follow-up period was 6.5 years. The mean Harris Hip Score improved from 40 to 90. All hips achieved immediate postoperative stability. No patient had thigh pain. Four hips had varus placement (5°–7°) of the stem; all were asymptomatic and remained stable without any migration. Evidence of proximal load transfer (endosteal spot welds) between the endosteum and the stem in zones 2 and/or 4 was noted in 12 hips on both sides and in 8 hips on the lateral side only. At one year, all stems showed evidence of osseointegration. None had subsidence or progressive varus migration. There was no radiolucent line or osteolysis around the stem, pedestal formation or buttressing at the prosthesis tip, or cortical hypertrophy. One patient had grade I heterotopic ossification that was not clinically significant. One patient had a 1.5 cm leg lengthening. One patient had a discharging sinus, a loosened acetabular component, and intrapelvic migration at 2 years and underwent implant removal and debridement. One patient developed a crack in the proximal femur even with the smallest stem. The stem was fixed with cerclage wiring and remained stable with no migration. Conclusion A short femoral stem design that transfers load proximally through a prominent lateral flare achieved good short-term outcome in younger patients. Nonetheless, the ease of removal and preservation of bone at the time of revision should guide the choice of the design of the short stem.